At present, wireless communication, for example, a telephone call using a mobile wireless communication terminal such as a mobile phone unit and the like is performed. An electromagnetic wave is radiated from an antenna of a mobile phone unit when making a telephone call. A part of the electromagnetic wave radiated is absorbed by the user using the mobile phone unit. It is desirable that the electromagnetic wave absorbed into the human body is low. Here, as one of the indices that show the amount of the absorption of the electromagnetic wave into the human body, there is the SAR that is the absorption rate of the electromagnetic wave energy applied to a specific portion of the human body. Hence, it is desirable that the SAR be reduced. However, if the electromagnetic wave radiated from an antenna is reduced just because the reduction of the SAR is desired, an antenna gain during a telephone call is dropped to cause a disadvantage to the telephone call.
Thus, it is preferable not to lower the antenna gain during a telephone call while improving the characteristic of the antenna and reducing the SAR. Hereupon, one in which the characteristic of the antenna is improved to control the interference between the antennas (refer to Published Japanese Patent Application No. 2003-163521), and one in which the reduction of the influence of the casing to the antenna (refer to Published Japanese Patent Application No. H9-270728) are proposed.
However, there is no such thing as the characteristic of the antenna is improved and the antenna gain during a telephone call is held while reducing the SAR.
Therefore, the present invention aims not to lower an antenna gain during a telephone call while reducing the SAR by improving the characteristic of the antenna.